Method for transmitting sub-frame designation information to a downlink in a radio communication system

ABSTRACT

A method of transmitting subframe designating information in downlink in a wireless communication system is disclosed. The present invention includes generating the subframe designating information for designating a subframe of a specific type in a radio frame and transmitting the generated subframe designating information to a user equipment, wherein the subframe designating information includes initial location information indicating an initial location of the subframe of the specific type on the radio frame and period information indicating a period for the subframe of the specific type to be repeated.

This application is a 35 U.S.C. §371 National Stage entry ofInternational Application No. PCT/KR2009/006609, filed on Nov. 11, 2009,and claims priority date to U.S. Provisional Application No. 61/113,233,filed Nov. 11, 2008 and Korean Application No. 10-2009-0050872, filed onJun. 9, 2009, which are incorporated by reference in their entireties.

TECHNICAL FIELD

The present invention relates to a mobile communication technology, andmore particularly, to a method of transmitting subframe designatinginformation in downlink.

BACKGROUND ART

In the following description, assume that ‘legacy system’ means apredefined system in advance and that ‘evolved system’ means a systemevolved from the legacy system or a newly defined system.

‘Legacy support’ means to support a legacy system in transmitting andreceiving relations with an evolved system. And, assume that thefollowing two conditions are met in a broad sense.

1) First of all, a legacy base station (hereinafter abbreviated BS) anda legacy mobile station (hereinafter abbreviated MS) are able totransmit and receive signals without being affected by an evolvedsystem. And, signal transmission and reception can be performed betweenthe legacy BS and an evolved MS.

2) Secondly, a BS available for both legacy and evolved systems are ableto transmit and receive signals to/from a legacy MS and an evolved MSboth.

For clarity and convenience of the following description, 3GPP LTE(3^(rd) generation partnership project long term evolution) system isassumed as a legacy system and 3GPP LTE-advanced (hereinafterabbreviated LTE-A) system is assumed as an evolved system.

After a basic configuration of system has been established, if a newservice is added, a problem of legacy support is always caused.Specifically, a system needs to be evolved in a direction for notaffecting performance of a legacy system. For this, an important controlchannel used for a legacy system should be protected. Yet, it is notpreferable that the protection for the legacy system degradesperformance of a new technical component.

FIG. 1 is a diagram of a radio FDD (frequency division duplexing) framestructure in 3GPP LTE system in case of a normal cyclic prefix (CP).

Referring to FIG. 1, in the radio frame structure, one radio frame(e.g., a length of the radio frame is 10 ms) is constructed with total10 subframes (e.g., a length of each subframe is 1 ms). And, usages ofsome of the subframes are specified. In particular, usages of 0^(th),4^(th), 5^(th) and 9^(th) subframes are specified as follows.

First of all, the 0^(th) and 5^(th) subframes (i.e., subframe 0 andsubframe 5 shown in FIG. 1) are configured to carry primarysynchronization channel (PSCH) and secondary synchronization channel(SSCH) for a synchronization signal, respectively. The 0^(th) subframeis configured to carry a physical broadcast channel (PBCH) as well asthe synchronization signal. Therefore, the 0^(th) subframe in a systemis configured to carry the SSCH, PSCH and PBCH and the 5^(th) subframeis configured to carry the SSCH and PSCH. A 4^(th) subframe (representedas subframe 4 in FIG. 1) is configured to carry SIB (system informationblock) information. And, a 9^(th) subframe (represented as subframe 9 inFIG. 1) is defined as a special subframe for unicast.

Particularly, in each of the 0^(th) and 5^(th) subframes, a 5^(th) OFDM(orthogonal frequency division multiplexing) symbol is an OFDM symbolfor carrying SSCH and a 6^(th) OFDM symbol is an OFDM symbol forcarrying PSCH. In the 0^(th) subframe, 7^(th) to 10^(th) OFDM symbolsare OFDM symbols for carrying PBCH.

FIG. 2 is a diagram for explaining a principle of HARQ (hybrid automaticrepeat request).

Referring to FIG. 2, HARQ is the hybrid technique generated fromcombining ARQ technique of MAC layer and channel coding scheme ofphysical layer together, as inferred from the name of the HARQ. In HARQ,since an initially transmitted packet, which is erroneous, is a signalP_(1A) having a prescribed information size, it is stored rather thandiscarded until a retransmitted signal is received. Soft combining isthen performed on the stored signal together with the retransmittedsignal P_(1B). Alternatively, a signal is decoded by a different methodusing the initially transmitted signal and the retransmitted signaltogether. In FIG. 2, the P_(1A) and the P_(1B) are rendered from thesame information bit, i.e., the same channel encoder input packet P₁ andare transmission packets identical to each other or slightly differentfrom each other, respectively. And, P_(2A) indicates a packet renderedfrom a new channel encoder input packet P₂.

In the above described frame structure, a physical structure of datacommunication uses HARQ but its period is defined as Hp (e.g., 8 ms).This means a structure that Hp processes can be carried on subframes bybeing interlaced, respectively. Hence, it can be observed that they canbe repeated with Hp subframe interval.

On the contrary, if a transmit unit of a radio frame transmitted by abase station is set to Rp, the radio frame is repeatedly transmitted bya period Rp (e.g., 10 ms) that is the transmit unit of the radio frame.

Under this circumstance, if a subframe of a specific type is designated,how to configure subframe designating information of the specific typecauses a problem. For instance, the subframe of the specific type caninclude one of MBSFN (Multimedia Broadcast multicast service SingleFrequency Network) subframe, relay subframe, blank subframe, Positioningsubframe, LTE-A subframe, and the like.

DISCLOSURE OF THE INVENTION Technical Problem Technical Solution

Accordingly, the present invention is directed to a method oftransmitting subframe designating information in downlink thatsubstantially obviates one or more of the problems due to limitationsand disadvantages of the related art.

In case that a subframe of a specific type is designated, an object ofthe present invention is to provide a method of transmitting informationon the designation in a wireless communication system.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims thereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, a method oftransmitting subframe designating information, which is transmitted indownlink in a wireless communication system, includes the steps ofgenerating the subframe designating information for designating asubframe of a specific type in a radio frame and transmitting thegenerated subframe designating information to a user equipment, whereinthe subframe designating information includes initial locationinformation indicating an initial location of the subframe of thespecific type on the radio frame and period information indicating aperiod for the subframe of the specific type to be repeated.

Preferably, the radio frame is a radio FDD (frequency divisionduplexing) frame, the radio frame includes 10 subframes, and thesubframe designating information includes the initial locationinformation and the period information on at least one of the rest ofthe 10 subframes except 0^(th), 4^(th), 5^(th) and 9^(th) subframes ofthe 10 subframes.

Preferably, the subframe of the specific type includes at least oneselected from the group consisting of an MBSFN (Multimedia Broadcastmulticast service Single Frequency Network) subframe, a relay subframe,a positioning subframe, an LTE-A (Long Term Evolution-Advanced)subframe, and a CSI-RS subframe.

To further achieve these and other advantages and in accordance with thepurpose of the present invention, a method of transmitting subframedesignating information, which is transmitted in downlink in a wirelesscommunication system, includes the steps of generating the subframedesignating information for designating a subframe of a specific type inat least one radio FDD (frequency division duplexing) frame andtransmitting the generated subframe designating information to a userequipment, wherein the at least one radio FDD frame includes 10 subframeand wherein the subframe designating information includes bitmapinformation for designating some of the 10 subframes to subframes of thespecific type.

Preferably, the bitmap information includes 6-bit information fordesignating the subframe of the specific type within the at least oneradio FDD frame, bits of the 6-bit information indicate whether 1^(st),2^(nd), 3^(rd), 6^(th), 7^(th) and 8^(th) subframes within the at leastone radio FDD frame are designated from the far left side of the 6-bitinformation to the subframes of the specific type. If each of the bitsis set to 1, it indicates that the corresponding subframe is set to thesubframe of the specific type.

Preferably, the bitmap information includes 24-bit information fordesignating the subframes of the specific type within 4 consecutiveradio FDD frames. In this case, bits of the 24-bit information indicatewhether 1^(st), 2^(nd), 3^(rd), 6^(th), 7^(th) and 8^(th) subframeswithin each of the radio FDD frames starting from a first one of the 4consecutive radio FDD frames are designated from the far left side ofthe 24-bit information to the subframes of the specific type, andwherein if each of the bits is set to 1, it indicates that thecorresponding subframe is set to the subframe of the specific type.

More preferably, the subframe of the specific type includes at least oneselected from the group consisting of an MBSFN (Multimedia Broadcastmulticast service Single Frequency Network) subframe, a relay subframe,a positioning subframe, an LTE-A (Long Term Evolution-Advanced)subframe, and a CSI-RS subframe.

To further achieve these and other advantages and in accordance with thepurpose of the present invention, a method of transmitting subframedesignating information, which is transmitted in downlink in a wirelesscommunication system, includes the steps of generating the subframedesignating information for designating a subframe of a specific type inat least one radio frame and transmitting the generated subframedesignating information to a user equipment, wherein the radio frameincludes a prescribed number of subframes and wherein the subframedesignating information includes pattern information representing alocation of the subframe of the specific type within the at least oneradio frame as a pattern.

Preferably, the at least one radio frame is a radio FDD (frequencydivision duplexing) frame, the radio FDD frame includes 10 subframes,and the subframe designating information includes the patterninformation for setting the rest of the 10 subframes except 0^(th),4^(th), 5^(th) and 9^(th) subframes of the 10 subframes to the subframesof the specific type.

Preferably, the subframe of the specific type includes at least oneselected from the group consisting of an MBSFN (Multimedia Broadcastmulticast service Single Frequency Network) subframe, a relay subframe,a positioning subframe, an LTE-A (Long Term Evolution-Advanced)subframe, and a CSI-RS subframe.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

Advantageous Effects

According to embodiments of the present invention, a subframe of aspecific type is designated within a radio frame while a legacy system(e.g., 3GPP LTE system) is supported. A user equipment can be theninformed of information on the designated subframe.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a diagram of a radio FDD (frequency division duplexing) framestructure in 3GPP LTE system in case of a normal cyclic prefix (CP);

FIG. 2 is a diagram for explaining a principle of HARQ (hybrid automaticrepeat request);

FIG. 3 is a flowchart for a method of transmitting subframe designatinginformation including initial location information and periodinformation of a subframe of a specific type according to one embodimentof the present invention;

FIG. 4 is a flowchart for a method of transmitting subframe designatinginformation including bitmap information of a subframe of a specifictype according to one embodiment of the present invention;

FIG. 5 is a flowchart for a method of transmitting subframe designatinginformation including pattern information according to one embodiment ofthe present invention; and

FIG. 6 is a block diagram for a configuration of a device applicable toa user equipment or a base station to implement the present invention.

BEST MODE Mode for Invention

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. In the following detailed description of the inventionincludes details to help the full understanding of the presentinvention. Yet, it is apparent to those skilled in the art that thepresent invention can be implemented without these details.

Occasionally, to prevent the present invention from getting vaguer,structures and/or devices known to the public are skipped or can berepresented as block diagrams centering on the core functions of thestructures and/or devices. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

The present invention proposes a periodic setting method and anon-periodic setting method as a method of setting a subframe of aspecific type within a radio frame. The subframe of the specific typecan include MBSFN (Multimedia Broadcast multicast service SingleFrequency Network) subframe. In case that a system supports a relay, thesubframe of the specific type can include a relay subframe or a blanksubframe. In case that LTE-A system is introduced as an evolved system,the subframe of the specific type can include a LTE-A subframe forsupporting LTE-A system, a positioning subframe for supporting ageographical positioning of a user equipment and CSI-RS (Channel StateInformation-Reference signal) contained subframe in which CSI-RS forchannel measurement exists, or the like.

As a type of setting a corresponding pattern periodically, it is able toconsider a scheme of indicating simply the type of a specific subframeor a scheme of indicating a specific pattern about the type of thespecific subframe.

The non-periodic setting method can consider a scheme of broadcasting atype of a subframe to a system at the timing point of setting the typeof the subframe or a scheme of unicasting a type of a subframe to aspecific user equipment (hereinafter abbreviated UE) or a target systemgroup at the timing point of setting the type of the subframe.

First Embodiment

In the following description, a periodic setting method is explained fora method of setting a subframe of a specific type within a radio frameaccording to one embodiment of the present invention.

For a method of setting a subframe of a specific type within a radioframe, in case of designating the subframe of the specific type, aperiodic setting method is characterized in setting a period of thedesignation to a predetermined value.

In particular, bitmap information, in which information on the settingof a type of each subframe within a radio frame is implemented into abitmap, is transmitted as system information together with a period andan offset value for a start point of applying the corresponding bitmap.Alternatively, initial location information of a subframe of a specifictype and information on a period indicating that the subframe of thecorresponding type appears with a prescribed period are transmitted.This may correspond to a case that a subframe of a specific type definedin one radio frame has a period of the radio frame. In this case, theradio frame can include a radio FDD (frequency division duplexing)frame.

For instance, a method of designating MBSFN subframe in a radioFrequency Division Multiplexing (FDD) frame (e.g., a length of the radioframe is 10 ms) is explained as follows. First of all, a radio FDD frame(e.g., a length of the radio frame is 10 ms) is constructed with total10 subframes (e.g., a length of each subframe is 1 ms). And, usages ofsome of the subframes are specified. In particular, usages of 0^(th),4^(th), 5^(th) and 9^(th) subframes are specified. Therefore, subframesavailable for designating subframes of specific type within one radioFDD frame include 1^(st), 2^(nd), 3^(rd), 6^(th), 7^(th) and 8^(th)subframes.

FIG. 3 is a flowchart for a method of transmitting subframe designatinginformation including initial location information and periodinformation of a subframe of a specific type according to one embodimentof the present invention.

Referring to FIG. 3, in a radio frame, a base station generates subframedesignating information including initial location informationindicating an initial location of a subframe of a specific type on theradio frame and period information indicating a period of repetition ofthe subframe of the specific type (S310). And, the base stationtransmits the generated subframe designating information to a userequipment (S320).

For instance, the subframe designating information can include initiallocation information of the subframe designated as a specific type among1^(st), 2^(nd), 3^(rd), 6^(th), 7^(th) and 8^(th) subframes and periodinformation indicating a period of repetition of the subframe of thespecific type.

FIG. 4 is a flowchart for a method of transmitting subframe designatinginformation including bitmap information of a subframe of a specifictype according to one embodiment of the present invention.

Referring to FIG. 4, in at least one radio FDD frame, a base stationgenerates subframe designating information including bitmap informationfor designating a subframe of a specific type (S410). And, the basestation transmits the generated subframe designating information to auser equipment (S420). Configurational contents of the bitmapinformation are explained as follows.

First of all, in configuring bitmap information for designating MBSFNsubframe, in case that the MBSFN subframe is designated within one radioFDD frame, there are total six subframes including 1^(st), 2^(nd),3^(rd), 6^(th), 7^(th) and 8^(th) subframes as subframes that can bedesignated as the MBSFN subframes. Hence, a bitmap is constructed with 6bits. And, the 6 bits are allocated in a manner of setting the 1^(st),2^(nd), 3^(rd), 6^(th), 7^(th) and 8^(th) subframes to the MBSFNsubframes in order starting from the far left side of the 6 bits. Ifeach of the bits is set to 1, it indicates that the correspondingsubframe is set to the MBSFN subframe. If the corresponding bit is setto 0, it indicates that the corresponding subframe is not set to theMBSFN subframe.

Alternatively, in configuring the bitmap information, it is able to setthe MBSFN subframes for the prescribed number of consecutive radio FDDframes instead of not being limited to one radio FDD frame only asmentioned in the foregoing description. For instance, in case ofdesignating MBSFN subframes for 4 consecutive radio FDD frames, sincethere are 6 subframes that can be designated as the MBSFN subframeswithin each of the radio FDD frames, a bitmap can be constructed with 24bits. And, the 24 bits are allocated in a manner of setting the 1^(st),2^(nd), 3^(rd), 6^(th), 7^(th) and 8^(th) subframes included in each ofthe 4 consecutive radio FDD frames to the MBSFN subframes in orderstarting from the far left side of the 24 bits. If each of the bits isset to 1, it indicates that the corresponding subframe is set to theMBSFN subframe. If the corresponding bit is set to 0, it indicates thatthe corresponding subframe is not set to the MBSFN subframe.

The above described MBSFN subframe designating method is usable todesignate another kind of subframe of a specific type as well as MBSFNsubframe. In this case, another kind of subframe of a specific type caninclude a relay subframe, a positioning subframe, an LTE-A subframe anda CSI-RS contained subframe.

Particularly, since a subframe of a specific type recognized by a legacyuser equipment includes only MBSFN subframe, when a subframe of aspecific type is generated by Rel-9 (release-9) system or LTE-A system,if the generated subframe of the specific type is set not to be accessedby the legacy user equipment, the corresponding subframe is set toMBSFN. And, the additional setting for this can be indicated again bythe above described type.

In doing so, the indicating method can be a method where the abovedescribed method is applied once more. On the contrary, a subframe,which causes no problem if accessed by a legacy user equipment, can beindicated by subframe type indication that is newly defined unlike afield indicating MBSFN subframe.

In one radio frame, a plurality of subframes of the same type can existwith different periods, respectively.

Meanwhile, in case of designating a subframe of a specific type based ona period, the subframe of the specific type can be overlapped with aspecific subframe of a legacy system according to the period.

In the above explained frame structure, a physical structure of datacommunication uses HARQ and its period is defined as Hp (e.g., 8 ms).This means a structure that Hp processes can be carried on subframes bybeing interlaced, respectively. Hence, it can be observed that they canbe repeated with Hp subframe interval.

On the contrary, if a transmit unit of a radio frame transmitted by abase station is set to Rp, the radio frame is repeatedly transmitted bya period Rp (e.g., 10 ms) that is the transmit unit of the radio frame.

For example, in case of LTE system, since 0^(th), 4^(th), 5^(th) and9^(th) subframes are defined as unicast, it may happen that a period ofa subframe of a specific type is periodically overlapped with the0^(th), 4^(th), 5^(th) and 9^(th) subframes, unless the period is not amultiple of 10 ms. In this case, although the 0^(th), 4^(th), 5^(th) and9^(th) subframes are taken as examples, they can be changed.

In LTE system, since a period of HARQ process is 8 ms, HARQ process IDrotates by 8 ms period. Hence, if a period of a subframe of a specifictype is not 8 ms, it may happen that the subframe of the specific typeis periodically overlapped with the HARQ process.

In order to prevent this situation, it is able to determine a period ofa subframe of a specific type based on a specific rule.

In particular, a period Sp of a subframe of a specific type can be setand a window Wp connected to the period Sp can be determined. If aprohibited subframe (e.g., the 0^(th), 4^(th), 5^(th) or 9^(th) subframein the LTE system) exists within a range of the window Wp at a positionof the period Sp, it is able to set a subframe having a biggest orsmallest index or a subframe closest to the Sp among the rest of thesubframes except the corresponding prohibited subframe to a subframe ofa specific type.

For instance, in case of LTE system, a period of a subframe of aspecific type can be set to Sp=8 ms and a window can be set to Wp=3 ms.Table 1 shows a location of a subframe of a specific type if a period ofa subframe of a specific type is set to Sp=8 ms and a window is set toWp=3 ms. In Table 1, ‘Rp’ indicates a transmit unit of a radio frametransmitted by a base station. In Table 1, an initial location value ofa subframe of a specific type is 1 and this value is changeable.

TABLE 1 Selection reference Subframe index Smallest index Rp * 0 + 1,Rp * 0 + 7, Rp * 1 + 7, Rp * 2 + 3, Rp * 3 + 3 Biggest index Rp * 0 + 1,Rp * 1 + 1, Rp * 1 + 7, Rp * 2 + 6, Rp * 3 + 2 Index closest to Sp Rp *0 + 1, Rp * 0 + 8, Rp * 1 + 7, Rp * 2 + 6, Rp * 3 + 3

In Table 1, a subframe index indicates the n^(th) time of a subframewithin a radio frame.

In Table 1, if a selection criteria is to select a small index, as aninitial location of a subframe of a specific type is 1 and a period Spis 8 ms, a next subframe should be 9^(th). However, since the 9^(th)subframe is prohibited to use, if the window Wp is applied in the 9^(th)subframe, the window Wp is applied toward a smaller index. Hence, it isable to designate 7^(th) and 8^(th) subframes to subframes of thespecific type. As it is supposed to select a subframe having thesmallest index, the 7^(th) subframe is finally selected.

In Table 1, if a selection criteria is to select a small index, as aninitial location of a subframe of a specific type is 1 and a period Spis 8 ms, a next subframe should be 9^(th). However, since the 9^(th)subframe is prohibited to use, if the window Wp is applied in the 9^(th)subframe, the window Wp is applied toward a smaller index. Hence, it isable to designate 7^(th) and 8^(th) subframes to subframes of thespecific type. As it is supposed to select a subframe having thesmallest index, the 7^(th) subframe is finally selected.

In Table 1, if a selection criteria is to select a big index, as aninitial location of a subframe of a specific type is 1 and a period Spis 8 ms, a next subframe should be 9^(th). However, since the 9^(th)subframe is prohibited to use, if the window Wp is applied in the 9^(th)subframe, the window Wp is applied toward a bigger index. Hence, it isable to select a 1^(st) subframe of a next radio frame as a subframe ofthe specific type. Yet, as it is supposed to select a subframe having asmallest index, the 7^(th) subframe is finally selected.

The rest of the subframes are selected in the same manner of the abovedescription.

In Table 1, if a selection criteria is to select an index closest to Sp,a subframe, which can be set to a subframe of a specific type byapplying a period Sp, is selected from subframes of the specific type.If the subframe having the period Sp applied thereto corresponds to oneof 0^(th), 4^(th), 5^(th) and 9^(th) subframes and is unable to beselected as the subframe of the specific type, subframes closest to the0^(th), 4^(th), 5^(th) and 9^(th) are selected as the subframes of thespecific type.

Although the above description is made by taking a radio FDD frame as anexample, the above method is applicable to a radio TDD (time divisionduplexing) frame as well. For instance, a radio TDD frame includes 10subframes. And, it is able to designate a subframe of a specific type byapplying the above method to at least one of the rest of subframesexcept the prohibited 0^(th), 1^(st), 4^(th) and 5^(th) subframes. And,the prohibited subframes are changeable.

Second Embodiment

For a method of setting a subframe of a specific type according to oneembodiment of the present invention, a hopping-pattern-based periodicsetting method will be explained in the following description.

FIG. 5 is a flowchart for a method of transmitting subframe designatinginformation including pattern information according to one embodiment ofthe present invention.

Referring to FIG. 5, in at least one or more radio frames, a basestation generates subframe designating information including patterninformation designating a subframe of a specific type (S510). And, thebase station transmits the generated subframe designating information toa user equipment (S520). In this case, the pattern information indicatesa location of the subframe of the specific type within the radio frameas a pattern. The pattern information will be explained as follows.

First of all, according to a hopping-pattern-based periodic settingmethod, after a pattern of a specific from has been predetermined, it isused by being designated by a system. For instance, a pattern of uniformselection for the number of specific radio frames (i.e., Nr radioframes) is predetermined. In this case, it is able to define a offsetuniform for a selected pattern in addition. After such a pattern hasbeen defined, when a system defines a subframe of a specific type, if aninitial subframe index value and pattern (offset can be announced inaddition) are determined, a user equipment keeps being aware of alocation of the subframe of the specific type.

Once the hoping pattern is determined in the above manner, it can beutilized to match a period failing to match another system operation byeasily hopping restrictions imposed on an irregularly appearingsubframe. For instance, in case of LTE system, a period of HARQ processis 8 subframes (1 ms for one subframe), a period of a radio frame is 10subframes (1 ms for one subframe), and unusable frames are 0^(th),4^(th), 5^(th) and 9^(th) subframes. For example, in case of generatinga pattern for minimizing influence on HARQ process, Table 2 shows anexample of hopping pattern in consideration of HARQ process period 8 ms.

TABLE 2 pattern ID Subframe index 0 (a = 0, Rp * 0 + a, Rp * 1 + a, Rp *2 + a, Rp * 3 + a 1, . . . , 9) 1 Rp * [−1, 0] + [8, 1], Rp * 0 + 8,Rp * 1 + 6, Rp * 2 + [3, 6], Rp * 3 + 2 2 Rp * 0 + 1, Rp * [0, 1] + [8,1], Rp * 1 + 7, Rp * 2 + [3, 6], Rp * 3 + 3 3 Rp * 0 + 2, Rp * [0, 1] +[8, 1], Rp * 1 + 8, Rp * 2 + 6, Rp * 3 + [3, 6] 4 Rp * 0 + 3, Rp * 0 +1, Rp * [1, 2] + [8, 1], Rp * 2 + 7, Rp * 3 + [3, 6] 5 Rp * 0 + [3, 6],Rp * 1 + 2, Rp * [1, 2] + [8, 1], Rp * 2 + 8, Rp * 3 + 6

In this case, a generated pattern is usable in a manner that its orderis randomly circular-shifted. In Table 2, [x, y] means that it can haveboth values of x and y. In Table 2, although prohibited subframes are0^(th), 4^(th), 5^(th) and 9^(th) subframes, the prohibited subframesare changeable if necessary.

In the following description, for a method of setting a subframe of aspecific type according to one embodiment of the present invention, anon-periodic setting method will be explained.

Third Embodiment

A non-periodic setting method is a scheme of announcing a type of asubframe based on scheduling instead of announcing a subframe type inthe above-described system information format. In particular, a locationof a subframe of a specific type is indicated at a start of acorresponding radio frame or a location, at which a subframe of aspecific type is always located, is indicated at a location of aspecific radio frame.

For instance, in LTE system, if 0^(th) subframe is not available foranother usage, it is able to adopt a scheme of announcing a definitionof one radio frame interval each time using 1^(st) subframe.

In this case, however, it is unable to avoid collision between the1^(st) subframe and HARQ process. Therefore, it is able to consider ascheme of announcing a type of a subframe occasionally once. Inparticular, if a period of HARQ process is 8 ms and a period of a radioframe is 10 ms, it is able to announce information on a subframe type ata specific location each 40 or 80 ms that is the common multiplein-between. If so, as HARQ process ID experiences collision at aspecific ID by a period of 40 or 80 ms only, this scheme can be regardedas a safe method. In doing so, it is possible to announce all types ofsubframes within a corresponding period. Such a long-durationannouncement of information is possible using system information aswell.

In case that a subframe type is announced using system information, theannouncement can be done by setting such a scheme of a bitmap.Alternatively, a combination of the aforesaid period using method andthe aforesaid hopping pattern using method is applicable to theannouncement.

If the periodic method among the above described methods, when asubframe of a specific type is designated, the method of designating asubframe of a specific type by preventing a case that the subframe ofthe specific type is overlapped with an index of a prohibited subframeis taken into consideration. The prohibited subframe can be defineddifferent according to a subframe of a specific type and may not existat all.

Actually, it may, however, happen that some of the prohibited subframesare usable. For instance, in case of LTE system, there existspossibility that 0^(th), 5^(th) and 9^(th) subframes among 0^(th),4^(th), 5^(th) and 9^(th) subframes are usable except the 4^(th)subframe. Therefore, in case of setting a period by allowing theoverlapping with theses subframes, setting for the overlapped subframesis necessary. In particular, instead of using one whole subframe, OFDMsymbols of the corresponding subframe are partially regarded ascorresponding to a specific subframe type.

For instance, 5^(th) and 6^(th) OFDM symbols in 0^(th) subframe are suedas SCH and 7^(th) to 10^(th) OFDM symbols in the 0^(th) subframe areused as PBCH. As a common reference signal and PDCCH exist, the OFDMsymbols remaining except the common reference signal and the PDCCH aredesignated to a specific subframe type to use. In particular, assumingthat a relay uses such a subframe, when the subframe is designated tothe relay, if a corresponding OFDM symbol is not for the relay, allsignal should be transmitted. And, a structure enabling a different workto be done in an OFDM symbol for the relay is possible.

If a case that a specific subframe type is overlapped with an index of aprohibited subframe is allowable, an accessible method can adopt thefollowing means different for each control channel.

1. SCH (Synchronization CHannel), PBCH (Physical Broadcast CHannel):

As the control signal is a signal that should be transmitted accordingto an initial access and intra/inter-RAT (Radio Access Technology)request, it must exist despite that a subframe type is overridden.

2. SIB (System Information Block):

If system information is transmitted in a structure of occupying onewhole subframe, it is unable to switch a type of this subframe toanother kind of subframe type. In this case, another adjacent subframeis used or hopped. If it is possible to transmit and receive signals byhaving the signals carried on different subcarriers on a frequency axis,respectively, a different type is usable even if such controlinformation configured to occupy one whole subframe as SIB.

3. Common Reference Signal

If it is determined that common reference signals exist enough tomeasure a channel, it is able to decrement the number of the commonreference signals. In particular, it is able to design a type ofsupporting common reference signals existing on specific OFDM symbol(s)instead of supporting all common reference signals spreading over onesubframe, i.e., a type of allowing first one or two OFDM symbols forexample of LTE system.

4. PDCCH (Physical Downlink Control Channel)+PHICH (Physical Hybrid ARQIndicator CHannel):

Length of such a control channel as PDCCH and PHICH is variableaccording to a value of PCFICH (Physical Control Format IndicatorCHannel) and can be limited to a specific value according to a subframetype. For instance, in case of a subframe type for a relay, the lengthcan be set to 0. In case of this setting, a corresponding subframe seemsto be a blank subframe in viewpoint of a user equipment or a basestation.

The above-described contents are applicable to a common reference signaland PCFICH, PDCCH, PHICH and the like as well as a use-prohibitedsubframe.

FIG. 6 is a block diagram for a configuration of a device applicable toa user equipment or a base station to implement the present invention.

Referring to FIG. 6, a device 600 includes a processing unit 601, amemory unit 602, an RF (radio frequency) unit 603, a display unit 604and a user interface unit 605. A layer of a physical interface protocolis performed by the processing unit 601. The processing unit 601provides a control plane and a user plane. A function of each layer canbe performed by the processing unit 601. The memory unit 602 iselectrically connected to the processing unit 601. And, an operatingsystem, applications and general files are stored in the memory unit602. If the device 600 is a user equipment, the display unit 604 is ableto display various kinds of informations. And, the display unit 604 canbe implemented using a well-known LCD (liquid crystal display), an OLED(organic light emitting diode) display and the like. The user interfaceunit 605 can be configured by being combined with such a well-known userinterface as a keypad, a touchscreen and the like. The RF unit 603 iselectrically connected to the processing unit 601. The RF unit 603transmits or receives a radio signal.

In this disclosure, embodiments of the present invention are describedcentering on the data transmission/reception relations between a basestation and a user equipment. In this case, the base station can includeeNB (evolved NodeB) and is meaningful as a terminal node of a networkwhich directly performs communication with a user equipment. In thisdisclosure, a specific operation explained as performed by a basestation can be performed by an upper node of the eNB in some cases.

In particular, in a network constructed with a plurality of networknodes including an eNB, various operations performed for communicationwith a UE can be performed by the eNB or other networks except the eNB.In this case, ‘eNB’ can be replaced by such a terminology as a fixedstation, a Node B, an access point and the like.

And, according to the present invention, ‘user equipment’ corresponds toa mobile station (MS). And, the mobile station (MS) can be replaced bysuch a terminology as a subscriber station (SS), a mobile subscriberstation (MSS), a mobile terminal and the like.

Moreover, a user equipment of the present invention can include one ofPDA (Personal Digital Assistant), cellular phone, PCS (PersonalCommunication Service) phone, GSM (Global System for Mobile) phone,WCDMA (Wideband CDMA) phone, MBS (Mobile Broadband System) phone and thelike.

While the present invention has been described and illustrated hereinwith reference to the preferred embodiments thereof, it will be apparentto those skilled in the art that various modifications and variationscan be made therein without departing from the spirit and scope of theinvention. Thus, it is intended that the present invention covers themodifications and variations of this invention that come within thescope of the appended claims and their equivalents. And, it isapparently understandable that an embodiment is configured by combiningclaims failing to have relation of explicit citation in the appendedclaims together or can be included as new claims by amendment afterfiling an application.

Embodiments of the present invention can be implemented using variousmeans. For instance, embodiments of the present invention can beimplemented using hardware, firmware, software and/or any combinationsthereof.

In the implementation by hardware, a method according to each embodimentof the present invention can be implemented by at least one selectedfrom the group consisting of ASICs (application specific integratedcircuits), DSPs (digital signal processors), DSPDs (digital signalprocessing devices), PLDs (programmable logic devices), FPGAs (fieldprogrammable gate arrays), processor, controller, microcontroller,microprocessor and the like.

In case of the implementation by firmware or software, a methodaccording to each embodiment of the present invention can be implementedby modules, procedures, and/or functions for performing theabove-explained functions or operations. Software code is stored in amemory unit and is then drivable by a processor. The memory unit isprovided within or outside the processor to exchange data with theprocessor through the various means known in public.

INDUSTRIAL APPLICABILITY

Accordingly, the present invention is applicable to an evolved system aswell as a legacy system.

1. A method of transmitting subframe designating information by a basestation, which is transmitted to one or more user equipments via adownlink in a wireless communication system, the method comprising:generating radio frame period information and offset information fordesignating at least one radio FDD (frequency division duplexing) framecontaining one or more target subframes; generating the subframedesignating information for designating the one or more target subframeswithin the at least one radio FDD frame designated by the radio frameperiod information and the offset information; and transmitting systeminformation comprising the radio frame period information, the offsetinformation and the subframe designating information to the one or moreuser equipments, wherein the at least one radio FDD frame includes0^(th) through 9^(th) subframes, each of the 10 subframes includes 2slots, and each of the 2 slots includes a predetermined number of OFDM(orthogonal frequency divisional multiplexing) symbols, and wherein thesubframe designating information has a bitmap in which each bit of thebitmap corresponds to each of a predetermined number of subframesselected from among all subframes within the at least one radio FDDframe, wherein each bit of the bitmap indicates whether or not each ofthe predetermined number of subframes is one of the one or more targetsubframes, wherein the bitmap includes 6-bit information for designatingthe one or more target subframes within one radio FDD frame, whereineach bit of the 6-bit information, from the leftmost bit of the 6-bitinformation, indicates whether 1^(st), 2^(nd), 3^(rd), 6^(th), 7^(th)and 8^(th) subframes within the one radio FDD frame are designated tothe one or more target subframes, and wherein if each bit of the 6-bitinformation is set to 1, it indicates that the corresponding subframe isset to one of the one or more target subframes.
 2. The method of claim1, wherein the one or more target subframes comprise at least oneselected from a group consisting of an MBSFN (Multimedia Broadcastmulticast service Single Frequency Network) subframe, a relay subframe,a positioning subframe, an LTE-A (Long Term Evolution-Advanced)subframe, and a CSI-RS (Channel Status Information-Reference Signal)subframe.
 3. The method of claim 1, wherein the bitmap comprisesinformation for designating the one or more target subframes within apredetermined number of radio FDD frames, wherein the predeterminednumber of radio FDD frames is predetermined considering a HARQ (HybridAutomatic Repeat Request) operation period.
 4. A base station apparatusfor transmitting subframe designating information, which is transmittedto one or more user equipments via a downlink in a wirelesscommunication system, the base station apparatus comprising: aprocessing unit for generating system information comprising radio frameperiod information and offset information for designating at least oneradio FDD (frequency division duplexing) frame containing one or moretarget subframes, and the subframe designating information fordesignating the one or more target subframes within the at least oneradio FDD frame designated by the radio frame period information and theoffset information; and a RF (Radio Frequency) unit, electricallyconnected to the processing unit, for transmitting the systeminformation generated by the processing unit to the one or more userequipments, wherein the at least one radio FDD frame includes 0^(th)through 9^(th) subframes, each of the 10 subframes includes 2 slots, andeach of the 2 slots includes a predetermined number of OFDM (orthogonalfrequency divisional multiplexing) symbols, and wherein the subframedesignating information has a bitmap in which each bit of the bitmapcorresponds to each of a predetermined number of subframes selected fromamong all subframes within the at least one radio FDD frame, whereineach bit of the bitmap indicates whether or not each of thepredetermined number of subframes is one of the one or more targetsubframes, wherein the bitmap includes 6-bit information for designatingthe one or more target subframes within one radio FDD frame, whereineach bit of the 6-bit information, from the leftmost bit of the 6-bitinformation, indicates whether 1^(st), 2^(nd), 3^(rd), 6^(th), 7^(th),and 8^(th) subframes within the one radio FDD frame are designated tothe one or more target subframes, and wherein if each bit of the 6-bitinformation is set to 1, it indicates that the corresponding subframe isset to one of the one or more target subframes.
 5. The base stationapparatus of claim 4, wherein the one or more target subframes compriseat least one selected from a group consisting of an MBSFN (MultimediaBroadcast multicast service Single Frequency Network) subframe, a relaysubframe, a positioning subframe, an LTE-A (Long TermEvolution-Advanced) subframe, and a CSI-RS (Channel StatusInformation-Reference Signal) subframe.
 6. The base station apparatus ofclaim 4, wherein the bitmap comprises information for designating theone or more target subframe subframes within a predetermined number ofradio FDD frames, wherein the predetermined number of radio FDD framesis predetermined considering a HARQ (Hybrid Automatic Repeat Request)operation period.
 7. A method of receiving subframe designatinginformation by a user equipment, which is received from a base stationvia a downlink in a wireless communication system, the methodcomprising: receiving system information comprising radio frame periodinformation and offset information for designating at least one radioFDD (frequency division duplexing) frame containing one or more targetsubframes, and the subframe designating information for designating theone or more target subframes within the at least one radio FDD framedesignated by the radio frame period information and the offsetinformation; and acquiring information of the one or more targetsubframes using the system information, wherein the at least one radioFDD frame includes 0^(th) through 9^(th) subframes, each of the 10subframes includes 2 slots, and each of the 2 slots includes apredetermined number of OFDM (orthogonal frequency divisionalmultiplexing) symbols, and wherein the subframe designating informationhas a bitmap in which each bit of the bitmap corresponds to each of apredetermined number of subframes selected from among all subframeswithin the at least one radio FDD frame, wherein each bit of the bitmapindicates whether or not each of the predetermined number of subframesis one of the one or more target subframes, wherein the bitmap includes6-bit information for designating the one or more target subframeswithin one radio FDD frame, wherein each bit of the 6-bit information,from the leftmost bit of the 6-bit information, indicates whether1^(st), 2^(nd), 3^(rd), 6^(th), 7^(th), and 8^(th) subframes within theone radio FDD frame are designated to the one or more target subframes,and wherein if each bit of the 6-bit information is set to 1, itindicates that the corresponding subframe is set to one of the one ormore target subframes.
 8. The method of claim 7, wherein the one or moretarget subframes comprise at least one selected from a group consistingof an MBSFN (Multimedia Broadcast multicast service Single FrequencyNetwork) subframe, a relay subframe, a positioning subframe, an LTE-A(Long Term Evolution-Advanced) subframe, and a CSI-RS (Channel StatusInformation-Reference Signal) subframe.
 9. The method of claim 7,wherein the bitmap comprises information for designating the one or moretarget subframes within a predetermined number of radio FDD frames,wherein the predetermined number of radio FDD frames is predeterminedconsidering a HARQ (Hybrid Automatic Repeat Request) operation period.10. A user equipment for receiving subframe designating information,which is received from a base station via a downlink in a wirelesscommunication system, the user equipment comprising: a RF (radioFrequency) unit for receiving system information comprising radio frameperiod information and offset information for designating at least oneradio FDD (frequency division duplexing) frame containing one or moretarget subframes, and the subframe designating information fordesignating the one or more target subframes within the at least oneradio FDD frame designated by the radio frame period information and theoffset information; and a processing unit, electrically connected to theRF unit, for acquiring information of the one or more target subframesusing the system information, wherein the at least one radio FDD frameincludes 0^(th) through 9^(th) subframes, each of the 10 subframesincludes 2 slots, and each of the 2 slots includes a predeterminednumber of OFDM (orthogonal frequency divisional multiplexing) symbols,and wherein the subframe designating information has a bitmap in whicheach bit of the bitmap corresponds to each of a predetermined number ofsubframes selected from among all subframes within the at least oneradio FDD frame, wherein each bit of the bitmap indicates whether or noteach of the predetermined number of subframes is one of the one or moretarget subframes, wherein the bitmap includes 6-bit information fordesignating the one or more target subframes within one radio FDD frame,wherein each bit of the 6-bit information, from the leftmost bit of the6-bit information, indicates whether 1^(st), 2^(nd), 3^(rd), 6^(th),7^(th), and 8^(th) subframes within the one radio FDD frame aredesignated to the one or more target subframes, and wherein if each bitof the 6-bit information is set to 1, it indicates that thecorresponding subframe is set to one of the one or more targetsubframes.
 11. The user equipment of claim 10, wherein the one or moretarget subframes comprise at least one selected from a group consistingof an MBSFN (Multimedia Broadcast multicast service Single FrequencyNetwork) subframe, a relay subframe, a positioning subframe, an LTE-A(Long Term Evolution-Advanced) subframe, and a CSI-RS (Channel StatusInformation-Reference Signal) subframe.
 12. The user equipment of claim10, wherein the bitmap comprises information for designating the one ormore target subframes within a predetermined number of radio FDD frames,wherein the predetermined number of radio FDD frames is predeterminedconsidering a HARQ (Hybrid Automatic Repeat Request) operation period.